Entries after this point are appreciated, but won't count for the competition!

Tomorrow I'll contact Colo, Hood, and Golly. We'll set up a google doc to put our comments in, and with any luck we'll have a winner within the week. After all, Christmas is in the way, and I don't expect anyone to do much work the coming few days!

The Knox class (at least) had Masker, so it didn't strictly require gas turbines. That said, as I recall the compressors to run it were said to be some of the most unreliable machinery aboard the steam frigates.

The original use was to silence diesel submarines in the Guppy series entering service around 1961 I believe, though it might be a couple years earlier. They replaced an entire diesel with an electrically driven compressor for both the Parrier and Masker functions, and that was just to make the submarine's own sonar work while snorkeling. They also installed an AC unit in some of this space. But the Guppy III went and added a hull plug that let them add that equipment without ditching a diesel, and solving a lot of other problems in the process.
Plans of this win herewww.hnsa.org/wp-content/uploads/2014/08/ss350.pdf

I believe the reason the Knox had problems with the Masker was basically non ideal placement of certain pipework, rather then any fundamental issues with (what I would guess) was probably a steam driven compressor. I've heard if you changed speed suddenly you could end up disabling the ships engines by sucking air into the condenser intakes. Which is a pretty awesome reason on the list of reasons why steam is amazingly terrible for shipboard power. Though the gas turbine driven systems are no magic, since you need a serious seawater driven chiller to cool down the air enough to be useful. Air tapped off a dedicated compressor comes out at the desired relatively low pressure and has less water to separate out. Obviously the actual turbine doesn't care about water in the intake air until we hit a force 17 typhoon, but everything using bleed air sure does.

In any case, if you have anything resembling working Typhon you are well past having the top secret bubble generators in service.